Is it possible to mount these on the wall at an angle? I was just thinking if you could angle them you could mount them in the corner well away from any rearing horses and they would sorta cross heat the area.

If I were hanging a heater from chains, I think I would
use a Quicklink or other closed chain linkage rather
than depending on closing a S hook with pliers. Just
to be a bit safer. And I might consider getting heavier
chains than the manufacturer supplies.